Dust Collectors vs Air Filters: How to Decide

Air quality in the work place is a major concern, and people in all types of jobs should be aware of air quality. Owners, managers, and employees should do what they can to maintain an acceptable level of airborne particle matter, chemicals, and allergens.

In many cases, this means using an air purifier, especially one that has a HEPA filter.

For some jobs, however, a more direct method is required. Industrial and manufacturing jobs that use metal or wood often have large amounts of solid matter resting on the floor or floating in the air.

Dust made of metal fragments can be a serious problem, and construction jobs and woodworking projects bring lots of sawdust and other large airborne particles, which can be inhaled by workers.

These types of jobs often require more than a basic air purifier.

In many cases, a dust collector will be used to capture particles and keep them from floating in the air and creating a mess on the ground. Dust collectors are an effective way to improve air quality, and when used in conjunction with an air cleaner, they can result in clean, healthy air in virtually any working condition.

Dust in the Workplace: More Common than We Might Think

It’s important to note that industrial dust in the work place is likely more common than you think. Many different jobs, especially “blue-collar” industrial and construction jobs can feature a high amount of dust.

The cement industry, as an example, can create a large amount of dust. Cement involves mining rock, crushing the materials, mixing and kilning the rock, milling, and bagging, storing, and transporting the finished product.

All of this can create massive amounts of dust which, if not properly controlled, can be inhaled at dangerous levels by people in the industry. This is just one example of dust in a specific job; if you think hard, you’ll find many more examples.

What is a Dust Collector?

These machines are designed to collect particles directly from the source where the dust is being created. Think of a wood sander with a dust-bag attachment that collects loose particles. With industrial-grade dust collectors, the same principle applies, only on a larger scale.

These systems are designed for high volumes of dust. They generally consist of a blower, which pulls air and dust into the unit, a filter, which takes out some of the finer particles, and a dust receptacle or bag, which collects the larger pieces, allowing you to dispose of them as needed.

Types of Dust Collectors

Baghouse Dust Collectors

A baghouse, also called a bag filter or fabric filter, is a system that removes particles from the air using the same principles as a bag attachment on a sander. They use long cylinder-shaped bags made from woven fabrics that act as a filter.

Essentially, dust-filled air enters the baghouse through various mechanisms, which often include a hopper, and then moves into the bags. The air is drawn through the porous bag, which results in a layer of dust collecting on the inside.

Cyclone Collectors

A cyclone dust collector, also known as an “inertial separator,” is a type of dust collector that works by centrifugal, inertial, or gravitational forces to separate dust from a stream of air.

When it is pulled from the air, the dust is moved into a hopper by gravity, where it is temporarily stored. Mainly, this type of collector is used for pre-cleaning, removing larger particles and rough debris, helping units that collect smaller particles avoid overload.

However, cyclone collectors can be used for many different purposes. These units may have single or multiple cyclones, or vortexes, that force dust from the air.

Wet Scrubbers

This method of dust collection uses a liquid, usually water, to “scrub” the air of dust particles. After going through rough filtration, the dust-filled air is sent through a mist, removing particles from the stream. The air is then moved through an outlet port and cycles through the system.

Wet scrubbers, also known as air scrubbers, are particularly useful for the collection of potentially explosive or flammable materials and in operations where the “slurry” (a combination of water and collected dust particles) could be reused.

For some types of materials, certain collection methods create chemical reactions, which makes wet scrubbers a popular choice.

Wet scrubbers generally have low start-up costs and require less space. They are also perfect for treating dust that comes out at a high temperature or with a high humidity.

However, wet scrubbers can be more costly to operate and require pre-cleaning of the air (such as cyclone collectors) before the air is ran through a mist.

Electrostatic Precipitators

When it comes to industrial dust and fine particles, electrostatic precipitators provide an effective solution. However, they do come with one specific drawback.

Essentially, electrostatic precipitators move air and dust through an electrical field, giving the particles an electrostatic charge. The particles are then collected on an area with an opposite charge, trapping them in place.

Basically, they use static cling to grab hold of dust.

These collectors are most effective when used to capture dust that comes in low volumes. For this reason, it’s usually best to run the dust-filled air through a series of air filters before moving it into the electrostatic precipitator.

However, they can be extremely efficient and can function effectively through a wide range of temperatures, making them ideal for industrial applications. They also provide a high flow rate, as the air is essentially unobstructed. They can not only collect fine particles, they are even useful for collecting materials such as acids and tar, which can present challenges for other systems.

Unfortunately, there is one specific drawback for using an electrostatic precipitator: ozone. These machines create trioxide, which is three oxygen atoms. This ozone is harmful for many reasons, so the use of electrostatic precipitators should only occur in controlled environments.

Unit Collectors

If a facility needs a conventional central collection system, the unit collector is often the best choice. These dust collectors are effective for controlling contamination at the source, have low initial costs, and low space requirements.

These are best used when the source of dust is isolated and portable, such as handheld equipment like a sander. There are many different designs for unit collectors, and they can be combined with cyclone technology or fabric collectors to provide high-quality, efficient dust collection.

There are other types of dust collectors that exist in the manufacturing and construction industries, but these are the main types that you will find in many of the facilities and operations across the country.

How are Air Purifiers Different?

Air purifiers are similar to dust collection systems, in that they also suck in air and clean it through a series of filters and other advanced technologies. The main difference, however, it that dust collectors are generally attached directly to the source of the dust.

A room air purifier sits in the corner, quietly taking in air and passing it through the filtration process, which can include HEPA filters, activated carbon, or even UV light, while a dust collector is usually attached, or very close to, industrial equipment.

Air purifiers make a wonderful addition to any workshop, and can help complement a dust collector to increase the effectiveness and performance. However, if you work in a location with high levels of dust, a standard air purifier will likely not provide the air-cleaning performance you need and may become overloaded with particles in the filter cartridge, leading to clogs and issues with airflow.

Air Cloth Ratio

An important factor that you’ll need to be aware of in air filtration is the air-cloth ratio.

Air cloth ratio, also known as air-to-media ratio, is a calculation of the amount of air that is able to go through a square foot of filter media material. It is a simple way to state the ratio between air movement and material size.

If a dust collector is moving at 4,000 cubic feet of air per minute (CFM) and had a medium size of 2,000 square feet, the ratio would be 4,000 to 2,000. However, this would be simplified to a 2:1 ratio. (2 cubic feet per minute for every square foot of space.)

To know the air-cloth ratio, simply take the amount of air passing through and divide it by the total square footage of the filter area.

This is an important number because it helps us know how long a certain medium will last under specific conditions. There are other factors the come into play, but this is a good guideline for filter life in dust collectors.

Generally, a unit with a low air-cloth ratio will have a shorter life. Low air-cloth ratios are best for air that has minimal amount of dust, dust-heavy air will usually need a higher air-cloth ratio.

What Types of Dust Exist in Your Work?

Dust is dust is dust...right? Wrong!

There are, in fact, about as many types or dust as there are industries that produce it.

Understanding what types of dust are produced in your industry or work, as well as the typical particle size, can help you choose the right collection methods.

Concrete Dust

Because of the nature of the materials, as well as the wide use, concrete dust is one of the most common forms of dust you will find.

Typically, dust is highly visible, so you can usually tell whether or not the dust is present. It can be abrasive, has a good flow with air dispersal, but it can also stay in the air for much longer. One of the challenges with concrete dust is that it has a wide range of particle sizes, requiring a versatile collection and filtering system.

Wood Dust

Like concrete dust, wood dust has a high variety of particle sizes, making diverse collection and filtration methods important. The biggest concern with wood dust is that it is both combustible and potentially explosive, creating fire and safety hazards in large concentrations.

Metal Dust

Many different industries produce metal dust. Depending on the specific metal, this can be one of the most dangerous forms of industrial dust. It is highly abrasive, creating the potential for significant long-term health problems.

Exposure to aluminum dust and fumes, for example, can actually bring impairment to cognition and movement and cholestasis, a condition that affects the liver, according to OSHA.

Rubber

Many products use rubber, but the most well-known product is, of course, the car tire. No matter what the specific industry, rubber manufacturing can produce dust that is combustible and even explosive in the right conditions.

It is also statically chargeable, which creates other hazards but also makes it susceptible to collection through electrostatic precipitators. Under certain conditions, it can be self-igniting.

According to a review of studies from numerous medical and scientific sources, working in the rubber-manufacturing industry creates many health hazards, including "leukemia, lymphoma, and cancers of the urinary bladder, lung, and stomach."

In addition, if stored indoors rubber can off-gas. A common chemical released from car tires is benzene. The best way to remove this dangerous gas is with ventilation. If you cannot properly ventilate your space, then using an air purifier with high quality activated carbon can adsorb it from the air.

Leather

Leather is similar to rubber when it is in dust form. It is combustible, potentially explosive, creating a surprising safety hazard. Studies have found that leather has the potential to cause cancer in the nasal cavities and sinus areas. As such, it is classified as a carcinogen.

Carbon Fibers

Carbon fiber is a polymer material that is also known as graphite fiber. It is stronger than steel and twice as stiff, but also incredibly lightweight, making it ideal for thousands of different products.

Carbon fiber is used in fishing rods, bicycles, aircraft, cars, plumbing, boat propellers, and more. The uses are practically limitless, but the dust created by manufacturing this material can be harmful. It has a medium flow velocity and is potentially combustible and explosive in certain concentrations.

Fiberglass

Not to be confused with carbon fiber, fiberglass is a reinforced material made from glass fibers embedded with resin and other adhesives to hold it together. It can be woven or in sheets, and is used in various products, automobiles, boat hulls, aircraft, electronics, insulation, and medical supplies. The material is also used for wind turbine blades (as is carbon fiber). Fiberglass presents challenges because it has a poor flow in the air. It is also abrasive on the skin or when inhaled, and can carry a static charge, creating significant hazards.

Plastic

Perhaps one of the most widely-used materials in the world, plastic comes in many different varieties, from light and flexible to dense, strong, and rigid. We won’t go too deep into the various forms of plastic (polyethylene terephthalate, anyone?) but just know that plastic dust in general can carry a static charge, be abrasive, and, depending on the type, could contain harmful chemicals.

Brick

Brick manufacturing requires working with clay, molding the materials, kilning the bricks, and drying them thoroughly. Even working with bricks in the final construction phase can result in exposure to brick dust, which has significant health hazards. It has a wide grain spectrum, so a variety of collection measures are required. It also has a high abrasiveness and in general it will have a high flow velocity.

Welding Fumes

If you are trained as a welder, you already understand the inherent health risks from this occupation. While many people know about the risks for vision, which require a welding mask, fumes from welding also create health problems. As a welder or anyone who works near welders, you could be exposed to free-flowing fumes and a fine dust, which require extremely fine filtering.

What Potential Health Issues Can Be Caused by Dust?

We already discussed some of the potential dust health issues with specific forms of industrial dust, but let’s take a closer look at some of the general health risks that are created by working in dusty conditions.

According to the World Health Organization, dust in general is linked to cancer, asthma, allergies, and a host of respiratory illnesses.

The specific health hazards largely depend on a wide range of factors. This includes the type of dust, the particle size, the concentration, and the length or exposure.

However, it’s not unheard of for dust to cause lung scarring, which can come from asbestos, irritation in the throat and lungs, pulmonary diseases, and toxic effects caused by the specific material, such as lead poisoning.

Fire Hazards and Dust

While most of this article has discussed controlling dust for the purpose of disease prevention and internal health, it’s important to note a specific safety hazard that comes with high concentrations of industrial dust: combustion or combustible dust.

Virtually any airborne dust that is flammable can be explosive, and combustible dust, such as wood dust, can be kicked up into the air and create fire and explosion hazards.

Static electricity, sparks from equipment, and high levels of heat can trigger an explosion or a fire. Almost any dust can become flammable, but high-risk materials include wood, plastics, resins, coal, carbon, iron, aluminum, and food products, such as flour or sugar.

To prevent flammable dust, good housekeeping is essential, starting with ventilation and collection of large dust particles, preferably straight from the source.

The Final Question: Deciding Between a Dust Collector and an Air Filter

All of thing brings us to the final question: should you use a dust collector or an air filter?

As we’ve learned, the effects of even light exposure, over time, can bring significant long-term health concerns for both you and your employees. For this reason, we recommend using both.

Essentially, if you are investing in a dust collector of any type for your industrial equipment, it will not hurt to supplement the collector with air purification technologies.

Depending on the type you select, the dust collector will be most beneficial for gathering the large particles of wood, metal, and plastics that are often found in factory settings.

The air purifier will then act as a fine particle collectors, filtering and trapping even the smallest bits of dust, while also collecting material such as mold spores, allergens, pollen, and dander.

When used together, an air purifier and dust collector can be an excellent combination.

EJ Air Purifier

Rated to clean an area measuring 1,500 square feet, the EJ Air Purifier is highly effective for removing dust from many different sources. It has a MERV rating of 17, which places it near the top in overall efficiency. According to tests, it can remove 99.99% of all airborne allergens and particles. It has two filters, including a nearly one-inch-deep activated carbon filter and a more than two-inch-deep main HEPA filter. These two filters make it one of the most versatile units you can have in your home, office, or workshop.

Erik 650A

With a MERV rating of 18, the Erik 650A is one of the most powerful and effective air purifiers you can own. It uses a proprietary gas filter that removes a wide range of gases, odors, and smoke, and can remove many of the smallest particles that escape the dust collector. It also uses an activated carbon filter in addition to a HEPA filter, but the HEPA filter in this unit is 12 inches thick, making it extremely effective when it comes to trapping particles. It’s so powerful that it can clean a 1,700-square-foot room at two air changes per hour.

Keep Your Home and Office Free of Dust with Oransi

Whether you need dust filtration for an industrial workshop or want to increase the quality of air in your home, the team at Oransi can help you select the right air purifier for your specific needs.

From commercial air purifiers to accessories and filters, we’ll make sure your area has clean, healthy air for everyone!

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